#include <bits/stdc++.h> #define int long long #define fi first #define se second #define mp make_pair #define Sz(x) (int)x.size() using namespace std; const int N = 2e5 + 5; int n, k, suf[N]; string s; void solve() { cin >> n >> k >> s; vector <int> sj, so, si; for (int i = 0; i < n; i++) { if (s[i] == 'J') sj.push_back(i); else if (s[i] == 'O') so.push_back(i); else si.push_back(i); } reverse(so.begin(), so.end()); reverse(si.begin(), si.end()); int ans = INT_MAX; for (int i = 0; i + k - 1 < Sz(sj); i++) { while (Sz(so) > 0 && so.back() <= sj[i + k - 1]) so.pop_back(); if (Sz(so) < k) break; while (Sz(si) > 0 && si.back() <= so[Sz(so) - k]) si.pop_back(); if (Sz(si) < k) break; int l = sj[i], r = si[Sz(si) - k]; ans = min(ans, n - (l + (n - r - 1)) - 3 * k); } if (ans == INT_MAX) cout << -1; else cout << ans; } signed main() { ios_base::sync_with_stdio(0); cin.tie(0); int tt = 1; // cin >> tt; while (tt--) { solve(); // cout << '\n'; } }